Electromagnetic talking machine



0a. 19, 1937. s BEGUM 2,096,445

ELECTROMAGNETIC TALKING MACHINE Filed June 6, 1955 MINI f0 fizvmzz az';

, fem/Bey? Patented Oct. 19, 1937 UNITED STATES PATENT OFFICE Semi Begun, Berlin, Germany, assignor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof,

Germany, a company Application June 6, 1935, Serial No. 25,353 In Germany June 9, 1934' 4 Claims.

In, the novel arrangement the circuit of the motor in order to be closed requires the set of spools to be fitted to the machine, so as to get interrupted whenever the set of spools is removed therefrom.

One embodiment of the invention is shown by way of example in the accompanying drawing, in which'Fig. l is a diagrammatic sectional elevation, of the assembled apparatus, only such parts being represented as are necessary for a complete understanding of the invention, and, Fig. 2 is a diagrammatic elevation similar to that shown in Fig. l with the record carrier removed from the frame. I

The set of spools comprises a casing I and two spools 3, 4 for the sound record carrier not shown, such as a steel tape or wire. 2 denotes the upper part of the machine. To the axle of the spool a screw-threaded spindle 5 is geared by bevel wheels l3. Spindle 5 carries a nut 6 adapted to interrupt either one or the other of two contacts I, 8 and thereby to open the circuit of amotor 9 which serves to drive the device in a manner not shown but well-known to those skilled in the art. The source of current is designated l0. I

The contacts I, 8 serve to cut out the motor as soon as the sound record carrier reaches the.

end of its movement. To rewind the sound rec- 40 ord carrier the spools may be turned back by hand far enough to close the contact I (or 8) and thus enable the motor circuit to be closed.

(Jontact I is shown as open and contact 8 shown as .closed. If now the set of spools I, 3, 4 is lifted from part '2, contact I closes since nut 6 then is withdrawn from this contact so as to cease to keep it open. As a result the motor 9 would be started if there were not in accordance with the invention a contact I l or a contact l2, or both of these contacts as shown by way of example, such contacts being disposed in the motor circuit-and closed by studs ll of the casing I, so that the motor circuit is interrupted whenever the set of spools is removed from part 55 2. Otherwise the sound record carrier might happen to be driven again on the removal of the set of spools and eventually tobe torn.

By providing, two such contacts, the motor circuit will be interrupted even if the set of spools is removed slantingly with respect to part ,2 so as to open either contact I I or contact I 2 first. For instance, if the set of spools is at first lifted at that end shown on the right-hand side of the figure then although contact ll remains closed the motor will not be started because contact |2 is allowed to open.

The invention is useful also without there being contacts such as those denoted by 1 and 8. In this case the advantage is attained that the motor cannot be started after the set of spools has been lifted ofi. This may be advantageous for exampleif the construction of the talking machine is such that there are rotating parts adapted to injure the user.

What is claimed is:

1. In an electromagnetic talking machine an interchangeable spool unit for carrying a flexible record-bearing filament, an electric drive circuit, a series of contacts serially included in said drive circuit 'and including two contacts .located in such positions as to be adjacent the ends of the spool unit when said spool unit is in its operative position, two contact operating portions on said spool unit adjacent the ends thereof, each of said portions being adapted to close one of the said two contacts in response to the correct positioning of the corresponding end of the spool unit whereby said two contacts are both closed only when said unit is in its operative position.

2. A device according to claim 1 having an element movable in correspondence with the travel of the flexible record-bearing filament, and in which the said series of contacts includes a further contact adapted to be opened by said element.

3. In an electromagnetic talking machine system an interchangeable spool unit adapted to carry a flexible record-bearing filament comprising a framepiece, two spools supported therefrom, a progressively movable element supported from said framepiece and means for progressively moving said element in response to the rotation of said spools, an electric drive circuit, a contact included in said drive circuit and adapted to be actuated in response to the progression of said element when said spool unit is in its operative position so as to open the said drive circuit when a predetermined amount of a flexible filament has been wound ofi from one of said spools onto the other, a pair of auxiliary contacts located in 1 spool unit when said spool unit is in its operative position, two contact operating portions on said spool unit adjacent the ends thereof, each of said portions being adapted to close one of the said auxiliary contacts in response to the correct positioning of the corresponding end of the spool unit wherebir at least one of the said contacts is opened in response to any displacement of the spool unit which is suflicientto bring the said progressive" element out of operative relation with the said first mentioned contact.

4. In an electromagnetic talking machine an interchangeable spool unit for carrying a flexible record-bearing filament comprising a framepiece, a first spool and a second spool supported from said iramepiece, a progressive element also supported from said iramepiece and means for progressively moving said element in response to the rotation of one of said spools whereby said element is moved to a first predetermined point in its path in response to the winding off of a predetermined length of said filament from the first spool onto' the second spool and is moved to a sec- 1 0nd predetermined point in its path in response to the winding on of a predetermined length of 7 said filament from the second spool onto the first 3,000,445 such positions 'as to be adjacent the ends of the spool: a frame separable from said spool unit;

driving means mounted on said frame and adapted to drive one oi said spools when the spool unit is in operative relation to said frame; a driving circuit for controlling said driving means; a first and a second switching device included in said circuit andsupported from said frame and respectively adapted to be opened in response to the progression of said element beyond said first and said second predetermined points when said switching devices'are in operative relation with the path of said element; two widely separated contacts mounted'on said frame and located insuch positions as to be adjacent the ends of the spool unit when said unit is in its operative position relative to said frame; two contact operating portions on the plate of said spool unit adjacent the ends thereof, each of said portions being adapted to close one of the saidcontacts, in response to the correct positioning of the corresponding end of the spool unit whereby said two contacts are both closed only when said unit is so positioned relative to said frame that said switching devices are operatively in the path of said progressive element. 

